I can only suggest to use isopropanol (not sure whats the english word but i think you guys will know). The good industrial stuff with high purity. You literally only need to fill you bong with like 100 ml, shake it around a little, rinse with it water afterwards and it will clean as fuck. I just cleaned my bong for the first time after many years and it took like 5 minutes to have it look new again.
I’m American and we also call it isopropyl alcohol but another common name for it here is rubbing alcohol (which is essentially a mixture of iso and water)
I’ve never needed anything more than that either. Tried plenty of gimmicky products back when I smoked but it never really made a difference. At best an additional abrasive but you can do that yourself as well if it’s truly necessary.
I can only suggest to use isopropanol (not sure whats the english word but i think you guys will know). The good industrial stuff with high purity. You literally only need to fill you bong with like 100 ml, shake it around a little, rinse with it water afterwards and it will clean as fuck. I just cleaned my bong for the first time after many years and it took like 5 minutes to have it look new again.
I’m American and we also call it isopropyl alcohol but another common name for it here is rubbing alcohol (which is essentially a mixture of iso and water)
I’ve never needed anything more than that either. Tried plenty of gimmicky products back when I smoked but it never really made a difference. At best an additional abrasive but you can do that yourself as well if it’s truly necessary.
There is a limit to how much iso or ethanol can do in my experience. Even the good stuff needs help.
Honestly just throw an abrasive in there along with the iso and that will bring those tricky spots to the finish line